作者:Shuntaro Sato、Yuki Fukuda、Yusuke Ogura、Eunsang Kwon、Shigefumi Kuwahara
DOI:10.1002/anie.201706086
日期:2017.8.28
unprecedented carbon skeleton were synthesized from ergosterol, both in 17 steps via a common secosteroidal intermediate. The conversion of ergosterol into the pivotal intermediate involved an efficient acid-catalyzed double-bond migration from ring B to ring D, oxidative cleavage of the double bond, and a completely diastereoselective acyl radical cyclization to form an isolated cyclopentanone ring unique
由麦角固醇通过普通的甾类甾体中间体,在17个步骤中合成了两种具有前所未见的碳骨架的表观异构体重排的麦角甾烷醇A和B,甾醇。麦角固醇向枢轴中间体的转化涉及从环B到环D的有效酸催化双键迁移,双键的氧化裂解以及完全非对映选择性的酰基自由基环化,形成了最近发现的独特的分离的环戊酮环蘑菇产生的甾体化合物家族。通过使用两种催化剂的氢化作用,将中间体立体发散地转化为两个差向异构环戊烷衍生物。利用碘化物的过酸氧化作用,将一种差向异构体精制为甾烷醇B,直接提供环氧化物,